Various antenna design techniques for medical applications

In this talk, various antenna design techniques for medical applications are introduced. Three types of antennas for medical application are proposed. To minimize the body effect, high dielectric material, zeroth-order resonance configuration, and an inverted-F structure with a meandered strip line techniques are utilized. I. An implanted compact antenna for an artificial cardiac pacemaker is proposed. The dimension of the pacemaker system, including the antenna element, is 30 mm × 35 mm × 7 mm. Taconic CER-10 with a relative permittivity of 10 is used for the substrate and two superstrates to reduce the effect of high conductive body tissue on the antenna. When the antenna is embedded in a semi-solid flat phantom with equivalent electrical properties as the human body, S11 value is -19.2 dB at 403.5 MHz. The measured specific absorption ratio (SAR) value of the proposed antenna is 0.0079 W/Kg (1 g tissue). Moreover, to estimate the communication performance of the proposed antenna operated in the real environment, a link budget analysis is performed. II. An implantable zeroth-order resonance (ZOR) antenna is proposed. By using chip inductors, an epsilon negative ZOR was generated, while achieving an extremely compact antenna size. The antenna has the overall dimensions of 0.021λ0 × 0.017λ0 × 0.002λ0 at the Medical Implantable Communication Service (MICS) band (402-405 MHz). Furthermore, the performance of the proposed antenna is insensitive to the electrical properties of the human body by virtue of the ZOR phenomenon. III. A capsule antenna used in an ingestible medical device is proposed. To achieve miniaturization and a wide bandwidth, an inverted-F antenna with a meandered strip line was used. The antenna performance in a human voxel model is analyzed through simulation, and the performance of the fabricated antenna is verified by comparing the measured data with that of the simulation when the antenna is placed in a human-equivalent liquid phantom.